LED projection lamps are mainly used as decorative lighting and also used for profiling large-sized buildings. The technical parameters thereof are basically similar to those of projection lamps. Relative to the round structure of LED projection lamps, it seems that the heat dissipation device of the strip-like structure of the LED lamp is more easily handled.
So far, projection lamps with a rolling structure have been seen in the projection lamp field. For example, the Chinese Patent Application No. 201510332599.3 (Chinese Patent Publication No. 106322292 A) discloses a projection lamp with a rolling snowflake effect, which comprises a projection device and a bracket disposed at the bottom of the projection device. In this structure, a motor is fixed in a housing; a rotating shaft of the motor is connected to a light condensing ball lens; the rotating shaft is radially opposite to a connecting rod portion, which is connected to a fixed part, relative to the center of the light condensing ball lens, which means that the rotating shaft is coaxial with the connecting rod portion. In this way, the projection lamp can project movable light, and the light effect is more gorgeous and can create different atmospheres. However, the following technical problems exist. In this projection lamp, the rotating shaft and the connecting rod portion are installed at the housing at the same time, which means that two symmetric ends are both connected to the housing. The rotating shaft and the connecting rod portion are coaxially arranged, so the light condensing ball lens has two points connected to the housing. If the light condensing ball lens rotates normally and smoothly, high requirements are imposed on the processing accuracy and installation accuracy of all the parts, resulting in difficulties in the processing and installation of the parts and high inflexibility in use.